The Siemens 5SJ6116-7KS is a 1-pole SENTRON miniature circuit breaker from the 5SJ6 family, rated 16 A with a C-curve tripping characteristic and a 6 kA breaking capacity per EN 60898.
The 6 kA breaking capacity at 400 V AC (per EN 60898, also rated 6 kA per IEC 60947-2) tells you it can safely interrupt a fault current up to that level without welding contacts or cascading upstream. At 1.9 W power loss per pole in hot operating state, the heat it dumps into a crowded DIN rail is low enough that you can mount it next to other breakers without forced derating in most residential or light-commercial panels.
Deployment context
Degree of pollution 2 and overvoltage category 3 are standard for fixed-installation distribution boards.